Air pervious composite fabric



Jan. 31, 1967 K. STIEHL ETAL 3,301,740

AIR PERVIOUS COMPOSITE FABRIC Filed June 6, 1963 INVENTORS ATTORNEYS United States Patent M 3,301,740 AIR PERVIOUS COMPOSITE FABRIC Karl Stiehl, Hanan am Main, and Heinrich Franz, Niederrodenbach, Germany, assignors t0 Deutsche Goldund Silber-Scheideanstalt vormals Roessler, Frankfurt am Main, Germany Filed June 6, 1963, Ser. No. 285,998 Claims priority, application Germany, June 6, 1962, D 24,909; Oct. 26, 1962, D 25,726 8 Claims. (Cl. 161-98) The present invention relates to an improved composite fabric which is pervious to air or other gases and vapors, and is particularly suitable for upholstery material as well as decorative material and many other uses for which leather substitutes are employed, especially where air permeability or breathability is desired.

Leather substitutes which do not have an impervious or continuous surface coating are already known. In these types of leather substitutes the pliable synthetic resin coating on the fabric is rendered pervious to air with the aid of chemical assistants, such as, for example, swelling agents, blowing agents, or by admixing substances which in themselves are swellable, such as starch, cork and the like, with the coating composition. A fur ther method of producing air permeable leather substitutes uses special coating apparatus which render it possible to produce discontinuous coatings, such as, for example, in the form of stripes or lattice work. Such discontinuous coatings have the disadvantage that the synthetic resin coating upon being subjected to sharp bends, and particularly upon being subjected to repeated bending in use, such as, for example, upholstery material for automobile seats, breaks relatively easily and also may separate from the fabric base.

According to the invention it was found that composite air permeable fabric which avoids the disadvantages mentioned above can be produced by joining a textile fabric base with fabric, the threads, strands or filaments of which are completely enveloped by a pliable synthetic resin by application of heat and pressure, the spacing or density of the synthetic resin envelop-ed threads, strands or filaments being such that upon being joined with the fabric base a finished composite fabric is provided having an air permeability, when measured according to German Industrial Standard DIN53334, of at least /2 liter per minute per 100 cm. of surface area at an air pressure differential of a 20 mm. water column. For simplicitys sake the term thread will be used hereinafter not only to designate twisted or untwisted strands but also fibers and filaments.

The fabrics employed for both the base fabric and the resin coated fabric can be in the form of woven, knitted or felled fabrics, fleeces, or so-called weftless fabrics 0r unwoven fabrics which are a type of fleece in which the juxtapositioned threads are only joined together at spaced intervals with a bonding agent such as a synthetic resin.

The textile fabrics used as the base for the composite fabrics according to the invention can be those normally employed in the production of leather substitutes, such as cotton or rayon fabrics, as well as fabrics of other synthetic fibers, such as, for example, nylon, polyester (Dacron), polyacrylonitrile, polycarbonates, polyurethanes, cross-linked polyvinyl chloride or polyvinylidene chloride and the like. As a general rule, the threads of the fabrics used as the base will be rather closely associated but still such as to provide sufi'icient porosity that 3,301,740 Patented Jan. 31, 1967 when joined with the relatively open resin coated fabric the resulting composite fabric has the necessary air permeability.

The fabrics employed for the relatively open resin coated fabrics preferably at least are partially formed of synthetic fibers or filaments which, for example, are produced from such materials as linear polycarbonamides (nylon, Perlon and the like), polyesters (Dacron and the like), polyacrylonitriles (Acrylon, Dynel, Orlon and the like), uncross-linked or cross-linked polyvinyl chlorides and polyvinylidene chlorides, polyurethanes, polycarbonates and the like.

The spacing between the threads of the fabrics employed for the resin coated fabrics preferably is such as to provide a thread density (count) of about 2 to 12 threads per cm., for example, in the warp and weft, with threads of a denier between about 1000 and 100. For example, with a fabric of 1000 denier polyester threads the thread density can expediently be selected between 2/2 and 7/7. With thinner threads of, for example, 250 or 210 denier, a higher thread density of up to 12/ 12 can be employed.

The ratio of synthetic resin to fabric in the synthetic resin coated fabric can vary depending on the thickness of the fabric threads as well as the spacing therebet-ween and must, of course, be selected in such a way that after being joined with the base fabric a composite fabric is produced in which the resin presented at the surface thereof is sufficiently discontinuous to provide the necessary permeability to air. With very open fabrics the resin envelope can be relatively heavier (thicker) than with fabrics of less open structure. In general, the quantity of synthetic resin employed in eoating'the open fabric amounts to at least 25% by weight of the open fabric and at most about 300% of the weight thereof. Preferably the quantity of resin is to 150% of the weight of the fabric coated therewith.

The pliable synthetic resins employed for embedment of the threads of the open fabric of the composite fabric preferably are of thermoplastic nature, especially plasticized polyvinyl chloride and copolymers of Vinyl chloride with vinylidene chloride. or vinyl acetate, polyacrylates, polymethacrylates, as well as the copolymers of acrylates and methacrylates with vinyl chloride, vinyl acetate, butadiene, styrene and the like. However, other resins which are not pronounced thermoplastic resins, such as,

I cross-linked polyurethanes, cross-linked polyvinyl chlo ride, vulcanizates of chlorobutadiene and of chlorosulfonated polyethylene or polypropylene or copolymers thereof. Also vulcanized natural or synthetic rubber can be embloyed for coating the threads of the open fabric of the composite fabric. Of course,

when such cross-linked or vulcanized products are concerned such, vulcanization or cross-linking is not effected until the coated fabric has been applied to the surface of the fabric base. Before such vulcanization or I cross-linking the resins or rubbers in question are still thermoplastic.

. such fabrics in the solutions or dispersions and stripping off the excess. When the solutions or dispersions are in a volatile organic solvent or mixture of such solvents, such solvent or solvents preferably are at least partially evaporated off before the coated fabric is joined with the fabric base. When the resins are, for example, ap-

plied in the form of plastisols, that is, as a dispersion of the resin in a solvent type plasticizer, pregelling of the resin is preferably effected before the coated fabric is joined with the fabric base. But if a volatile solvent has been added to reduce the viscosity thereof, the volatile solvent is first evaporated off and the remaining resin plasticizer mixture heated to effect pregelation on the threads of the open fabric.

The union between the resin coated open fabric and the fabric base is effected by the application of pressure and/ or heat. For example, the resin coated fabric can be calendered onto the fabric base while hot or it can be calendered on while cool or warm and subsequently heated to perfect the union, for example, by effecting complete gelation, cross-linking or vulcanization.

According to specially advantageous embodiments of the invention it was found desirable to provide for a contrast between the fabric base and the resin of the coated open fabric joined therewith, either as to color or texture. For example, the fabric base can be colored red or gray and the resin colored white or some other contrasting color so that, for example, a composite fabric is obtained having a network of contrasting stripes on a gray or red background. In addition, it is possible to emboss the surface of the resin portion of the composite fabric to provide grained or rippled surface effects Such embossing can be elfected with the usual embossing calenders used in making leather substitutes. In addition, portions of the surface of the resin portion of the composite fabric may have further contrasting colors printed thereon as such or in conjunction with the embossing operation.

It furthermore has been found advantageous to employ fabrics as the fabric base which have been given the best and longest lasting special finishes, such as, for example, water and soil repelling finishes, crease resistant finishes, mildew resistant finishes, rot resistant finishes and insect resistant finishes. Also, it has been found advantageous to give the entire composite fabric a treatment with a water repellant material, such as, for example, a silicone (polysiloxane).

In the accompanying drawings:

FIG. 1 shows a top plan view of a composite fabric according to the invention; and

FIG. 2 shows an enlarged cross-section of such composite Ifabric taken along line 22 of FIG. 1.

In such drawings, the open fabric 1, for example, of polyester fiber, bearing coating 2 of resin, for example, plasticized polyvinyl chloride, is united with the fabric base 3, for example, cotton twill.

The following examples will serve to illustrate the invention.

Example I A woven netting of endless nylon fibers (thread strength 840 denier) with a thread count of 3/3 per cm. was dipped into a polyvinyl chloride plastisol (60% polyvinyl chloride, 40% dioctylphthalate) provided with a gray pigment and the excess plastisol stripped off. Immediately thereafter the thus coated netting was passed through a chamber heated to 170180 C. at such a rate that itv remained in such heated chamber for about 510 minutes to effect gelation of the plasticized polyvinyl chloride. The thus coated netting was then calendered at a pressure of about 9-10 atmospheres onto a cotton twill fabric base (250 g./m. which had been dyed black, on an embossing calender such as customarily employed in the substitute leather manufacture. The coated netting was heated to about 150l70 C. with infra red radiation before it was supplied to the calender. The veocity of the calender was maintained between about 4-6 meters per minute. The gray coated netting which had been united with the fabric base provided a pleasing contrast with the black color of such base. 4

The resulting composite fabric exhibited an air permeability of 150 liters per minute when measured according to DIN53334, and was excellently suited as upholstery material for automobile seats which, as is known, are subjected to extremely hard wear.

Example 2 parts by weight of a mixture of the following composition:

Parts by weight Chlorosulfonated polyethylene 100.0

Stearic acid 2.0 MgO (light) 20.0 ZnO (active) 5.0 Kaolin 70.0 Carbon black (coloring) 0.2 Cumarone resin 3.0 Ti0 5.0 Vulcanization accelerator (dithiocarbamate) 2.0

were mixed into 200 parts by weight of a 2:1 solvent mixture of toluene and ligroin (B.P. 80-l10 C.) and the resulting mixture homogenized.

A woven netting of polyester fibers (thread strength 1000 denier, thread count 2.5/2.5 per cm.) was dipped once into such homogenized mixture and the excess was stripped off so that upon evaporation of the solvent the quantity of dry substance adhering to the netting was 75% by weight of the polyester netting.

The thus coated fabric while still slightly damp with solvent was applied with light pressure to a black woven cotton fabric base (thread count 27/20 per mm., yarn No. (metric) Nm 34/24), dried for 20 minutes at 80 C. and then vulcanized under light pressure for /2 hour at C.

The air permeability of the resulting composite fabric was 370 liters per minute per 100 cm. area at a pressure of 10 mm. water column.

Example 3 A woven netting of endless nylon fibers (thread strength 840 denier) with a thread count of 3/ 3 per cm. was dipped into a polyvinyl chloride plastisol (60% polyvinyl chloride, 40% dioctylphthalate) provided with a gray pigment and the excess plastisol stripped off. Immediately thereafter the thus coated netting was passed through a chamber heated to 180 C. at such a rate that it remained in such heated chamber for about 5l0 minutes to effect gel-ation of the plasticized polyvinyl chloride. The thus coated netting was then calendered at a pressure of about 9-10 atmospheres onto a dark red air pervious cotton fabric base (thread count 27/20 per om., yarn No. (metric) Nm 34/24) which had been rendered mildew resistant with a textile assistant based on sodium phenolate on an embossing calender such as customarily employed in the substitute leather manufacture. The coated netting was heated to about ISO-170 C. with infra red radiation before it was supplied to the calender. The velocity of the calender was maintained between about 4-6 meters per minute. The gray coated netting which had \been united with the fabric base provided .a plea-sing contrast with the dark red color of such base.

The resulting composite fabric exhibited an air perme- Example 4 100 parts by weight of a mixture of the following composition:

Parts by weight Butadiene acrylonitrile copolymer containing 33% acrylonitrile Perbunan N3307NS 23.1 Fillers:

Active precipitated calcium silicate (Calsil) 8.1 Chalk 5.8 Pigment and dye:

Ti0 2.3 Yellow dye 0.2 Paraflin (M.P. 52-54 C.) 0.5 Stearic acid L 0.1 Colloidal sulfur 0.5 Mercaptobenzothiazole 0.1 Mixture of alkylated phenols 0.2 2-mercaptobenzimidazole 0.2 Benzyl octyl adipate 2.3 Double saltof Zn-ethylphenyl-dithiocarbarnate and cyclohexylethylamine 0.3 Xylene 30.6 Toluene 5.1 Ethyl acetate 15.3

were mixed into 100 parts by weight of a 621:3 mixture of Xylene, toluene and ethyl acetate.

A woven netting of nylon fibers (thread count /10 per cm., thread strength 21-0 denier) was dipped into such mixture and dried for 20 minutes at 80 C. and again dipped into such mixture and then lightly pressed onto a fabric base (same as in Example 2) and vulcanized for 5 minutes at 110 C.

The air permeability of the resulting composite fabric was of the same order as that of Example 2.

We claim:

1. A composite fabric comprising an air pervious fabric base (1) having at least one surface united with a superposed relatively open fabric (2) the threads of which are surrounded by a coating of pliable synthetic resin the thread count and coating of pliable synthetic resin of said open fabric (2) being such that such composite fabric has an air permeability of at least /2 liter per minute per cm. area at a pressure differential of 20 mm. water column said air pervious fabric base (11) having a substantially higher thread count than said relatively open fabric and being essentially uncoated by said pliable synthetic resin other than by that carried by the superposed relatively more open fabric (2) united therewith.

2. A composite fabric according to claim 1 in which the thread count per cm. of said relatively open fabric is between 2-l2 per cm. and the threads have a denier between 1000 and 100.

3. A composite fabric according to claim 1 in which the coating surrounding the threads of the relatively open fabric is betwen 25% and 300% by weight of such open fabric.

4. A composite fabric according to claim 1 in which said pliable synthetic resin is thermoplastic.

5. A composite fabric according to claim 1 in which said pliable synthetic resin is plasticized polyvinyl chloride.

6. A composite fabric according to claim 1 in which the color of the fabric base is contrasting to the color of the plastic coating on the relatively open fabric joined therewith.

7. A composite fabric according to claim 1 in which the synthetic resin surface provided on the composite fabric by the resin coated relatively open fabric joined With the fabric base is embossed.

8. A composite fabric according to claim 1 in which the synthetic resin surface provided on the composite fabric by the resin coated relatively open fabric joined with the fabric base carries a discontinuous overpn'nt of contrasting color.

References Cited by the Examiner UNITED STATES PATENTS 2,268,616 l/l942 Peters 161- 98 2,673,824 3/1954 Biefield et a1. l17-135.5 X 2,798,820 7/ 1957 Nelson.

ALEXANDER WY=MA*N, Primary Examiner.

D. H. ROBESON, M. LITMAN, Assistant Examiners. 

1. A COMPOSITE FABRIC COMPRISING AN AIR PERVIOUS FABRIC BASE (1) HAVING AT LEAST ONE SURFACE UNITED WITH A SUPERPOSED RELATIVELY OPEN FABRIC (2) THE THREADS OF WHICH ARE SURROUNDED BY A COATING OF PLIABLE SYNTHETIC RESIN THE THREAD COUNT AND COATING OF PLIABLE SYNTHETIC RESIN OF SIAD OPEN FABRIC (2) BEING SUCH THAT SUCH COMPOSITE FABRIC HAS AN AIR PERMEABILITY OF AT LEAST 1/2 LITER PER MINUTE PER 100 CM.2 AREA AT A PRESSURE DIFFERENTIAL OF 20 MM. WATER COLUMN SAID AIR PERVIOUS FABRIC BASE (1) HAVING A SUBSTANTIALLY HIGHER THREAD COUNT THAN SAID RELATIVELY OPEN FABRIC AND BEING ESSENTIALLY UNCOATED BY SAID PLIABLE SYNTHETIC RESIN OTHER THAN BY THAT CARRIED BY THE SUPERPOSED RELATIVELY MORE OPEN FARIC (2) UNITED THEREWITH. 